Microsatellite markers for population-genetic studies of shiitake (Lentinula edodes) strains

Analysis of Genetic Diversity and Population Structure of Wild Strains and Cultivars Using Genomic SSR Markers in Lentinula edodes

In this study, the genetic diversity and the population structure of 77 wild strains and 23 cultivars of Lentinula edodes from Korea were analyzed using 20 genomic SSRs, and their genetic relationship was investigated. The tested strains of L. edodes were divided into three sub-groups consisting of only wild strains, mainly wild strains and several cultivars, and mainly cultivars and several wild strains by distance-based analysis. Using model-based analysis, L. edodes strains were divided into two subpopulations; the first one consisting of only wild strains and the second one with mainly cultivars and several wild strains. Moreover, AMOVA analysis revealed that the genetic variation in the cultivars was higher than that in the wild strains. The expected and observed heterozygosity and values indicating the polymorphic information content of L. edodes cultivars from Korea were also higher than that of the wild strains. Based on these results, we presume that the cultivars in Korea have developed by using numerous strains from other countries. In conclusion, the usage of wild strains for the development of new cultivars could improve the adaptability of L. edodes to biotic and abiotic stress.

Association Mapping Reveals Genetic Loci Associated with Important Agronomic Traits in Lentinula edodes, Shiitake Mushroom

Association mapping is a robust approach for the detection of quantitative trait loci (QTLs). Here, by genotyping 297 genome-wide molecular markers of 89 Lentinula edodes cultivars in China, the genetic diversity, population structure and genetic loci associated with 11 agronomic traits were examined. A total of 873 alleles were detected in the tested strains with a mean of 2.939 alleles per locus, and the Shannon's information index was 0.734. Population structure analysis revealed two robustly differentiated groups among the Chinese L. edodes cultivars (F_ST = 0.247). Using the mixed linear model, a total of 43 markers were detected to be significantly associated with four traits. The number of markers associated with traits ranged from 9 to 26, and the phenotypic variations explained by each marker varied from 12.07% to 31.32%. Apart from five previously reported markers, the remaining 38 markers were newly reported here. Twenty-one markers were identified as simultaneously linked to two to four traits, and five markers were associated with the same traits in cultivation tests performed in two consecutive years. The 43 traits-associated markers were related to 97 genes, and 24 of them were related to 10 traits-associated markers detected in both years or identified previously, 13 of which had a >2-fold expression change between the mycelium and primordium stages. Our study has provided candidate markers for marker-assisted selection (MAS) and useful clues for understanding the genetic architecture of agronomic traits in the shiitake mushroom.

Identification of Single Nucleotide Polymorphism Markers in the Laccase Gene of Shiitake Mushrooms (Lentinula edodes)

We identified single nucleotide polymorphism (SNP) markers in the laccase gene to establish a line-diagnostic system for shiitake mushrooms. A total of 89 fungal isolates representing four lines, including Korean registered, Korean wild type, Chinese, and Japanese lines, were analyzed. The results suggest that SNP markers in the laccase gene can be useful for line typing in shiitake mushrooms.